This invention refers to the use of packets formed by the junction of a plurality of sheets in plastic material, shaped in relief, laid one upon the other and welded together, for the realization of protection barriers for impact absorption, especially for motor car and cycle courses.
These packets are realized by shaping sheets in plastic material in such a way as to produce ribs and/or hollow protruding parts, superimposing them so that these protruding parts lean against the protruding parts of the contiguous sheet, in order to realize empty spaces between these sheets, and then welding the sheets together, in order to obtain a packet of considerable thickness that in case of impact plastically warps, absorbing gradually the kinetic energy and softening the impact. The elements according to the invention are, thanks to their characteristics, especially suitable for the realization of protection barriers both for motor car courses and for motor cycle courses.
As it is known, one of the most severe problems in the organization of motor contests is the safety problem, both for drivers and public.
As far as the course safety is concerned, during the years many solutions have been proposed in the attempt to realize barriers able to assure an appropriate protection to both public and drivers.
The rigid barriers, generally formed by guardrails or by a wall in reinforced concrete, often completed with a net of appropriate height, show themselves effective for the protection of the public but often dangerous for the safety of the drivers.
This kind of barrier, in fact, is suitable only when the impact angle between vehicle and wall is little enough to allow the vehicle to slide along the barrier, that gradually slackens its speed.
In case of frontal impacts, however this solution is extremely dangerous.
For a certain period of time barriers were used formed by straw bales leaned against rigid barriers, with a certain improvement with reference to the previous barriers, as a certain possibility of compliance, that lessens the violence of a frontal impact, is associated to a low coefficient of tangential friction, that helps the sliding along the barrier itself.
This solution showed to be of a certain utility only in case of motor cycle tracks and did not show an appropriate level of protection in case of impact of a racing car.
Also in case of motor cycle courses, besides, the effectiveness of these barriers could be furtherly improved if it were possible to increase the compliance transversely.
More over, the straw bales show other inconveniences as for instance the inflammability of the material.
Another kind of barriers often used in motor car courses is formed by a series of tires leaned against a rigid barrier and fastened with ropes.
The tire barriers yield more than the previous ones, but show two serious inconveniences: on the one hand there is in fact the risk that this barrier opens, entrapping the vehicle and/or the driver, who cannot slide but must stop, on the other hand the ability of this material to get elastically deformed, tending to return part of the energy absorbed during the impact, lets the vehicle rebound again to the middle of the track, with the consequent seriously dangerous situation.
Recently protection barriers were proposed formed by a series of containers in a material capable of being deformed, for instance in plastic material, joined together and partially filled with water.
These barriers show a compliance comparable to the compliance of the tires, with the advantage to have a smooth surface with low friction, that allows the vehicle to slide along it.
But also this method is inadequate in case of frontal impact because these containers, compressed in consequence of the impact, return then elastically to the initial position, repelling the vehicle and/or the driver towards the track.